Venezuelan President Hugo Chávez Tuesday told reporters in Hanoi that he contacted Havana over the phone, following announcement that Cuban ruler Fidel Castro temporarily ceded power to his brother, Raúl Castro, because of health problems.

Chávez would not elaborate on his phone conversation, but confirmed that Castro "temporarily" transferred power to Raúl Castro because of "digestive problems," Efe reported.

The Venezuelan ruler added that officials in Havana ensured that Castro would be back in office "in a few weeks."

The Cuban leader's secretary, Carlos Valenciaga, read a letter Monday night that he said was from Fidel Castro announcing the news. In it, the Cuban ruler said that stress had forced him into surgery and that he would be in bed for several weeks after the operation.

Castro, who has led Cuba since the 1959 revolution, turns 80 on August 13.

"This kind of news is worrisome. I hope from the bottom of my heart that Fidel Castro recovers as soon as possible, so that he can be with us always," the Venezuelan ruler added.

"Long live Fidel Castro!" Chávez exclaimed before reporters in Vietnam, where he is paying a two-day official visit ending Tuesday.

Chávez' next stop in his world tour is Mali.